Centers for Disease Control and Prevention

National Center for Immunization and Respiratory Diseases

Photographs and images included in this presentation are licensed solely for CDC/NCIRD online and presentation 

use. No rights are implied or extended for use in printing or any use by other CDC CIOs or any external audiences.

COVID-19–Associated Hospitalizations among 

Infants, Children and Adults — COVID-NET, January–

August 2023

ACIP, September 12, 2023

Fiona P. Havers, MD, MHS

Team Lead, RESP-NET Hospitalization Surveillance Team

Surveillance and Prevention Branch

Coronavirus and Other Respiratory Viruses Division
▪ RESP-NET: COVID-NET, RSV-NET, FluSurv-NET

▪ >300 acute-care hospitals

▪ 98 counties in 13 states

▪ In 9 of 10 HHS regions

▪ ~10% of U.S. population

▪ Positive SARS-CoV-2 within 14 days of or 

during hospitalization

▪ Screening or clinician-driven testing

▪ Clinical data: representative sample of 

COVID-NET patients

COVID-NET: A RESP-NET population-based hospitalization 

surveillance platform

2
Weekly Population-Based Rates of COVID-19-Associated 

Hospitalizations — COVID-NET, March 2020–August 26, 

2023

0

20

40

60

80

100

120

140

3/7/2020

5/7/2020

7/7/2020

9/7/2020

11/7/2020

1/7/2021

3/7/2021

5/7/2021

7/7/2021

9/7/2021

11/7/2021

1/7/2022

3/7/2022

5/7/2022

7/7/2022

9/7/2022

11/7/2022

1/7/2023

3/7/2023

5/7/2023

7/7/2023

Rate per 100,000 population

Week Ending Date

March 1, 2020–August 26, 2023

<6 months 6 months–4 years 5–11 years 12–17 years

18–49 years 50–64 years 65–74 years ≥75 years

0

20

40

60

80

100

120

140

Rate per 100,000 population

Week Ending Date

January 1–August 26, 2023

Gray boxes indicate potential reporting delays. Interpretation of trends should be excluded from these weeks. 

Rates highest in ≥75 years, followed by 

infants <6 months and adults 65–74 years

3
Epidemiology of COVID-19–associated 

hospitalization among children
0

10

20

30

40

50

60

70

80

Rate per 100,000 population

Week Ending Date

<6 months 6 months–4 years 5–11 years 12–17 years

Gray boxes indicate potential reporting delays. Interpretation of trends should be excluded from these weeks. 

Weekly Population-Based Rates of COVID-19-Associated 

Hospitalizations among Infants, Children, and Adolescents 

≤17 Years — COVID-NET, March 2020–August 26, 2023

5
Gray boxes indicate potential reporting delays. Interpretation of trends should be excluded from these weeks. 

0

2

4

6

8

10

12

14

16

18

20

3/7/2020 6/7/2020 9/7/2020 12/7/2020 3/7/2021 6/7/2021 9/7/2021 12/7/2021 3/7/2022 6/7/2022 9/7/2022 12/7/2022 3/7/2023 6/7/2023

Rate per 100,000 population

Week Ending Date

6-23 months 2-4 years 5–11 years 12–17 years

Focus on 6 months-17 years of age

Weekly COVID-19-Associated Hospitalization Rates among 

Infants, Children and Adolescents Ages 6 months – ≤17 Years 

— COVID-NET, March 2020–August 26, 2023

6
Percent of COVID-19-Associated Hospitalizations with Underlying 

Medical Conditions among Children and Adolescents Ages 5–17 Years 

by Age Group — COVID-NET, January–June 2023

Data are limited to hospitalizations where COVID-19 is a likely primary reason for admission. Figure displays underlying medical conditions present in ≥5% in ≥1 age group.

• 54% of hospitalized 

infants, children, and 

adolescents ages 

≤17 years have no

underlying medical 

conditions.

• Hospitalizations 

children and 

adolescents ages ≥5 

years are more 

likely to have 

underlying medical 

conditions relative 

to children and 

infants ages ≤4 

years.

0

5

10

15

20

25

30

35

40

Weighted % of COVID

<6 months 6–<2 years 2–4 years 5–11 years 12–17 years

-19 associated 

hospitalizations

Prematurity Asthma

Neurologic disorders Obesity

Immunocompromising condition Cardiovascular disease

Feeding tube dependence Chronic lung disease, not including asthma

Blood disorders Chronic metabolic diseases, including diabetes

34% with no 

underlying 

conditions

59% with no 

underlying 

conditions

42% with no 

underlying 

conditions

23% with no 

underlying 

conditions

75% with no 

underlying 

conditions

7
0

50

100

150

200

250

10/9/2021 1/9/2022 4/9/2022 7/9/2022

Rate per 100,000 population

Week Ending Date

≤4 years (COVID-19) ≤4 years (Influenza)

5–11 years (COVID-19) 5–11 years (Influenza)

12–17 years (COVID-19) 12–17 years (Influenza)

0

50

100

150

200

250

10/8/2022 11/26/2022 1/14/2023 3/4/2023 4/22/2023 6/10/2023

Rate per 100,000 population

Week Ending Date

≤4 years (COVID-19) ≤4 years (Influenza)

5–11 years (COVID-19) 5–11 years (Influenza)

12–17 years (COVID-19) 12–17 years (Influenza)

Cumulative Weekly Rates of COVID-19- and Influenza-Associated 

Hospitalizations among Infants, Children, and Adolescents Ages 

≤17 Years — COVID-NET and FluSurv-NET*, October 2021—July 2023

October 2021–September 2022 October 2022–July 2023

* Influenza Hospitalization Surveillance Network. Seasonal FluSurv-NET surveillance was extended into June for the 2021-2022 season. Surveillance ended on April 30, 2023, for the 2022–2023 

season. Hospitalization rates are among those with laboratory-confirmed influenza and SARS-CoV-2 and are not adjusted for likely reason for admission. 8
21

27

26 25

32

16

19

17 17

23

0

5

10

15

20

25

30

35

<6 months 6 months–<2 years 2–4 years 5–11 years 12–17 years

Percent of Hospitalizations

COVID-19 Influenza

Percent of COVID-19- and Influenza-Associated Hospitalizations 

with ICU Admission among Infants, Children, and Adolescents 

by Age Group — COVID-NET and FluSurv-NET*, October 2022–

April 2023

• Influenza Hospitalization Surveillance Network

Limited to COVID-NET hospitalizations with COVID-19-related illness as likely reason for admission

9
Vaccination Status by Age Group among Infants, Children and 

Adolescents Ages ≤17 Years Hospitalized for COVID-19 —

COVID-NET, January–June 2023

Data are limited to hospitalizations where COVID-19 is a likely primary reason for admission. Unvaccinated: No recorded doses of COVID-19 vaccine. Vaccinated, but no bivalent booster: 

Completed a primary series with or without ≥1 booster dose but did not receive an updated bivalent booster dose. Updated bivalent booster: Received updated bivalent booster dose. 

Partially vaccinated: Received at least one dose of COVID-19 but was not considered fully vaccinated at the time of a positive SARS-CoV-2 test. Persons with unknown vaccination status 

are excluded. 

86

63

26

8

28

63

4 6

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

6 months–4 years 5–11 years 12–17 years

Percent of COVID-19-asssoicated 

hospitalizations

Unvaccinated Vaccinated, but no bivalent booster Updated bivalent booster Partially vaccinated

10
Epidemiology of COVID-19–associated 

hospitalizations among adults
Weekly Population-Based Rates of COVID-19-Associated 

Hospitalizations among Adults Ages ≥18 Years — COVID-NET, 

March 2020–August 2023

0

20

40

60

80

100

120

140

Rate per 100,000 population

Week Ending Date

March 1, 2020–August 26, 2023 (entire pandemic period)

18–49 years 50–64 years 65–74 years ≥75 years

0

20

40

60

80

100

120

140

Rate per 100,000 population

Week Ending Date

January 1 –August 26, 2023

Gray boxes indicate potential reporting delays. Interpretation of trends should be excluded from these weeks. 12
Underlying Medical Conditions among Adults Ages ≥18 Years Hospitalized 

for COVID-19, by Age Group — COVID-NET, January–June 2023

27

49

66

22

38 39

31

26

36

40 41

29

23

17

10

21

33 33

14

17 16

8

14

6

14

7

5

2

5 4

13 12

24

9

25

28

0

10

20

30

40

50

60

70

18–49 years 50–64 years ≥65 years

Weighted % of hospitalizations

Cardiovascular disease Diabetes

Neurologic disorders Obesity

Asthma Chronic lung disease, not including asthma

Immunocompromising condition Gastrointenstinal/liver Disease

Blood disorders Autoimmune/inflammatory disease

Chronic metabolic disease, not including diabetes Renal disease

Data are limited to hospitalizations where COVID-19 is a likely primary reason for admission.

18–49 years:

58% with ≥3 underlying 

conditions

50–64 years:

72% with ≥3 underlying 

conditions

≥65 years:

81% with ≥3 underlying 

conditions

13
Cumulative Weekly Rates of COVID-19- and InfluenzaAssociated Hospitalizations among Adults Ages ≥18 Years —

COVID-NET and FluSurv-NET*, October 2022–July 2023

0

50

100

150

200

250

10/8/2022 12/8/2022 2/8/2023 4/8/2023 6/8/2023

Rate per 100,000 population

Week Ending Date

Adults ages 18–64 years

18–49 years (COVID-19) 18–49 years (Influenza)

50–64 years (COVID-19) 50–64 years (Influenza)

* Influenza Hospitalization Surveillance Network. Seasonal FluSurv-NET surveillance ended on April 30, 2023, for the 2022–2023 season.

0

500

1000

1500

2000

2500

10/8/2022 12/8/2022 2/8/2023 4/8/2023 6/8/2023

Rate per 100,000 population

Week Ending Date

Adults ages ≥65 years

65–74 years (COVID-19) 65–74 years (Influenza)

75–84 years (COVID-19) 75–84 years (Influenza)

≥85 years (COVID-19) ≥85 years (Influenza)

14
Percent of COVID-19- and Influenza-Associated Hospitalizations with 

ICU admission among Adults by Age Group — COVID-NET and FluSurvNET*, 13 States, October 2022–April 2023

• Influenza Hospitalization Surveillance Network

Limited to COVID-NET hospitalizations with COVID-19-related illness as likely reason for admission

19

22

18

7

11

14

18

17

12

8

0

5

10

15

20

25

18–49 years 50–64 years 65–74 years 75–84 years ≥85 years

Percent of COVID-19- and

Influenza-associated Hospitalizations

COVID-19 Influenza

15
Percent of COVID-19- and Influenza-Associated Hospitalizations with inhospital death among Adults by Age Group — COVID-NET and FluSurvNET*, 13 States, October 2022–April 2023

2.1

4.0

6.4

4.9

4.1

0.7

2.9

3.1

4.3

4.6

0

1

2

3

4

5

6

7

18–49 years 50–64 years 65–74 years 75–84 years ≥85 years

Percent of COVID-19- and

Influenza-associated Hospitalizations

COVID-19 Influenza

• Influenza Hospitalization Surveillance Network

Limited to COVID-NET hospitalizations with COVID-19-related illness as likely reason for admission

16
Vaccination Status by Age Group among Non-Pregnant 

Adults Ages ≥18 Years Hospitalized for COVID-19 — COVIDNET, January–June 2023

Data are limited to hospitalizations where COVID-19 is a likely primary reason for admission. Unvaccinated: No recorded doses of COVID-19 vaccine. Vaccinated, but no bivalent booster: 

Completed a primary series with or without ≥1 booster dose but did not receive an updated bivalent booster dose. Updated bivalent booster: Received updated bivalent booster dose. 

Partially vaccinated: Received at least one dose of COVID-19 but was not considered fully vaccinated at the time of a positive SARS-CoV-2 test. Persons with unknown vaccination status 

are excluded. 

35

26

17

11

53

58

61 69

8 13 19 19

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

18–49 years 50–64 years 65–74 years ≥75 years

Percent of COVID-19-associated 

hospitalizations

Unvaccinated Vaccinated, but no bivalent booster Updated bivalent booster Partially vaccinated

17
▪ Hospitalization rates increased in all age groups since mid-July

▪ Hospitalization rates highest in older adults and infants <6 months

▪ Most children <5 years hospitalized with COVID-19 illness have no underlying medical 

conditions

– A higher proportion of hospitalized children and adolescents 5-17 years have 

underlying medical conditions

– Most hospitalized adults have multiple underlying medical conditions

▪ COVID-19 continues to cause severe illness; clinical outcomes generally comparable to 

influenza-associated hospitalizations

▪ Most children and adults hospitalized for COVID-19 since January 2023 had not 

received an updated bivalent booster

COVID-19-associated hospitalizations

18
Coronavirus and Other Respiratory 

Viruses Division

Chris Taylor

Kadam Patel

Meredith McMorrow

Influenza Division

Shikha Garg

Catherine Bozio

Alissa O’Halloran

Dawud Ujamaa

RESP-NET Site investigators and staff

Acknowledgements
For more information, contact CDC

1-800-CDC-INFO (232-4636)

TTY: 1-888-232-6348 www.cdc.gov

The findings and conclusions in this report are those of the authors and do not necessarily represent the official 

position of the Centers for Disease Control and Prevention.

Photographs and images included in this presentation are licensed solely for CDC/NCIRD online and presentation 

use. No rights are implied or extended for use in printing or any use by other CDC CIOs or any external audiences.